[leetcode299] 299. Bulls and Cows

public String getHint(String secret, String guess) {
    /*
    判断bull 是通过比较两个字符串的每一位，每次相同就删除该字符出现的次数，因为后边的
    要判断cow不能占用这些
    判断cow只要检测出去被占用的还有没有该字符
     */
    //key记录字符，value记录出现的次数
    Map<Character,Integer> map = new HashMap<>();
    String res = "";
    int a = 0;
    int b = 0;
    boolean[] boo = new boolean[secret.length()];
    for (int i = 0; i < secret.length(); i++) {
        char cur = secret.charAt(i);
        int num = map.getOrDefault(cur,0);
        num++;
        map.put(cur,num);
    }
    //判断bull和cow不能一起，要先判断bull，因为如果在判断cow的过程中会占用，会影响bull
    for (int i = 0; i < guess.length(); i++) {
        char cur = guess.charAt(i);
        if (cur==secret.charAt(i))
        {
            a++;
            boo[i] = true;
            map.put(cur,map.get(cur)-1);
        }
    }
    for (int i = 0; i < guess.length(); i++) {
        char cur = guess.charAt(i);
        if (!boo[i]&&map.containsKey(cur)&&map.get(cur)>0)
        {
            b++;
            map.put(cur,map.get(cur)-1);
        }
    }
    res = a+"A"+b+"B";
    return res;
}